For Safety's Sake
is a story with a lesson learned by the author and thousands of others
ever since electric power appliances and tools first became available.
Fortunately, his Ham buddy was not permanently harmed, but even today
with all the effort put into educating the public, people continue to
use ungrounded (2-wire type, or with the ground prong removed) extension
cords in conjunction with 3-wire power cords on tools and end up electrocuting
themselves (or somebody else). I've told the story before about a friend
of mine from high school who shortly after graduation was making a piece
of furniture in a garage that had a damp dirt floor, and was electrocuted
to death by the metal-framed circular saw that had no ground connected.
Nowadays we often have power provided by a GFCI receptacle when working
outdoors or under a house, but I sure would not rely on it performing
properly in lieu of taking prudent safety precautions. Hopefully you
December 1966 QST
Wax nostalgic about and learn from the history of early electronics. See articles
QST, published December 1915 - present. All copyrights hereby acknowledged.
For Safety's Sake
By H. W. Morgan, M.D.,* K0JTP
quad had been in the air for six year and needed to be checked over.
K0IDN, a nearby ham friend, provided a gin pole and enough rope from
his hay-lift equipment to lower the quad for inspection. I knew there
was a loose connection somewhere in the system as a high wind caused
an intermittent make and break in the signals.
I usually hire
a professional climber to do my high work, ever since I spent a summer
vacation in the hospital as a result of a flag pole breaking with me
at the age of 16. However, two young hams, Tom and Cap, volunteered
to do the climbing for me. A safety belt was provided and a safety rope
was rigged for the second climber.
The quad came down easily.
We had thought about that when we put it up; only two bolts twisted
off in the removal process and these were easily replaced. The bad connection
was found to be a coax fitting which had been improperly soldered.
A slight modification had to be made to the yoke supporting the
quad boom. The old yoke was removed and replaced with a new one. This
necessitated the drilling of four holes in a floor-flange bearing plate
attached to the upper end of the pipe used in rotating the quad from
the ground. The two boys accomplished this, working together at the
top of the tower with a quarter-horse electric drill powered by a heavy-duty
extension cord. Three of the four holes had been drilled and the bolts
inserted with Tom working alone at the top of the tower when the accident
Cap and I were on our backs on the ground watching
the procedure when a cry came from Tom at the top of the tower. Being
a physician, I first thought that Tom was an epileptic and had suffered
an epileptic attack. Cap, however, was an old lineman and shouted that
it appeared Tom had been electrocuted. Fortunately, he was mistaken.
For an old man I really made time around the corner of the house, fell
as I made the turn, but was able to grab the extension cord close enough
to the plug to remove it, even while I was falling. Tom immediately
dropped the drill which he had been unable to release before that time.
I insisted that he wait at the top of the tower before unhooking the
safety belt until George could climb up to help him. He made it down
without difficulty and within thirty minutes was back at the top of
the tower helping replace the quad. There was not even a burn on his
hand which held the drill, or on his feet where he was in contact with
the tower except for a pair of tennis shoes. What had happened?
The drill is a heavy-duty job and is provided with a ground wire
but this was not used, since the extension cord was a 2-wire type. The
drill was all of 25 years old and the ground wire had long since broken
off at the plug end. Only a short length remained of the ground cord
and this was doubled up inside the plug. I had tested the drill on the
previous day, using the same long extension cord at the base of the
tower, and the boys had drilled several holes on this occasion without
experiencing any difficulty. In checking the drill immediately after
the accident, I found the ground wire exposed and in close proximity
to one of the rivets holding a plug contact in place. It is possible
that the ground wire touched this rivet and the polarity was such that
the metal case of the drill was on the hot side of the line. My wife
also told me that during the time we were working, the electric current
in the house went off at least twice for a few seconds. Remodeling of
the substation supplying our power is in progress and it was thought
that this was responsible for the interruption.
What can be learned
from this near-fatal accident? First, never work alone. Have someone
on the ground capable of disconnecting any electric circuit. You have
four minutes in which to restore circulation to the brain either by
cardiac massage or artificial respiration. Otherwise, brain damage will
result even though life may be restored. Second, a safety belt or rope
must be used. Heavy tools, such as the electrical drill, should be secured
with a line, too. Last but not least, remember that a trusted tool may
develop a defect.
My new extension cord is a 3-wire cord and
the few remaining 2-wire plugs in my home, shop, and ham shack will
soon be converted, for safety's sake.
Copyright: 1996 - 2024
BSEE - KB3UON
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